title: Posterior dislocation of the Oxford knee meniscal bearing: a treatment option.
abstract: Unicompartmental knee replacement (UKR) is now established as a treatment for medial compartment arthritis. The Oxford UKR (Biomet Orthopedics, Inc, Warsaw, IN, USA) has a mobile-bearing system, which minimizes wear. This has been shown to provide excellent long-term results. Dislocation of the mobile-bearing device is rare with an incidence of 1 in 200 (0.5 %). The treatment usually involves exploration of the knee through the original anteromedial incision, removal of the dislocated bearing and rectification of the underlying cause for the dislocation. We describe two cases of a posterior dislocation in which the mobile bearing could not be retrieved and was left in situ. In both cases a good outcome was achieved. We conclude that in extremely rare cases where a dislocated bearing has migrated posteromedially and cannot be retrieved, it can be left in place rather than exploring the joint acutely through a separate posterior incision.
authors.forename: S
authors.initials: S
authors.lastname: Tibrewal
authors.forename: H
authors.initials: H
authors.lastname: Pandit
authors.forename: P
authors.initials: P
authors.lastname: McLardy-Smith
authors.forename: S B
authors.initials: SB
authors.lastname: Tibrewal
authors.forename: D W
authors.initials: DW
authors.lastname: Murray
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods*; D020878:Device Removal / Q000379:methods; D005260:Female; D006801:Humans; D031221:Knee Dislocation / Q000000981:diagnostic imaging / Q000601:surgery*; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000601:surgery; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D011475:Prosthesis Failure; D016896:Treatment Outcome; D014463:Ultrasonography